Apparatus for roasting sodium bicarbonate



(No Model.)

B. SOLVAY.

APPARATUS FOR ROASTING SODIUM BIGARBONATE.

Patented July 24, 1888.

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ERNEST SOLVAY, OF BRUSSELS, BELGIUM, ASSIGNOR TO THE SOLVAY PRO- CESS COMPANY, OF SYRACUSE, NEXV YORK.

APPARATUS FOR ROASTING SODIUM BICARBONATE.

SPECIFICATION forming part of Letters Patem. No. 386.664, dated July 24, 1888.

Application filed March 29, 1898. Serial No. 268.886.

(Ne model.) Paleted in Belgium August l1.1-`87,No. 78,547; in France August ll, 1887, No.1S5,*28-2, and in England October 1, 1587, No. 13,323.

Be it known that l, ERNEST SOLVAY,0f Brussels, Belgium, have invenled new and useful Improvements in Furnaces for the Decomposition of Bcarbonate ot' Soda, (for which I have obtained foreign patents in England, October 1, 1887, No. 13,323; in France, August 11, 1887, No. 185282, and in Belgium, August 11, 1887, No. 78,547.) of which the following, taken in connection with the accompanying drawings, is a full, clear, and exact description.

This invention relates to an inprovenentin furnaces for the decomposition of bicarbonate of soda; and it consists in certain peculiarities of the Construction and arrangement of the same, substantially as will be hereinafter more i'ully set forth and claimed.

In order to enable others skilled in the art to which my invention pertains to make and use the same, I will now proceed to descrihe its Construction and operation, referring to the acconpanying drawings, in which- Fignre lis a lougitudinal section of my device, and Fig. 2 is a cross-section of the discharge end of the cylinder.

a represeuts a t'urnace of any usual or dcsired form, provided with grate-bars a' and ashpit a as usual. Over this t'nrnace, set in brickwork or other suitable material, is a eylinder, b, conposed of three parts, as shown in Fig. 1, said parts being rigidly securcd together, and of considcrable length in proportion to its diameter. This cylinder is supported upon rollcrs b' and provided at one end with a toothed ring or gear, If, by which it is revolved by connection with any desired motive power.

The working of the bicarbonate of *soda is better eftected by the admixture with it of a small quantity of soda already calcined, and I effect this mixtnre, as well as the proper and regular feeding of the bicarbonate, by means of the following devices:

The bicarbonate is fed into a hopper, c, in the bottom of which is a revolving feeder, c which feeds the material regularly and evenly into a cylindrical chamber, 0 upon which the hopper is set. This chamber is provided with a longitudinal shaft, d, having arms d', acting to stir the material and break up any lumps into which it may be forned, and connected with the rear end of this cylindrical chamber c is a pipe, (P, connected to a suitable source ofsupply, provided with a conveyer screw, (1 for feeding in therequisitequantity of calciued soda, which is mixed with the bicarbonate of soda in the chanber 6-'. It will be noted that the conveyer screw d ends just before reaching the end of the pipe in which it acts, thus causing the calcined soda to collect in and fill the end ot' the pipe, forming an air-tight plug therein, for a purpose prescntly explained.

The cylindrical chamber 0 is connected by a pipe, e, with the forward end of the revolving cylinder b, and the material is fed through this pipe to the roasting-cylinder, through which it slowly passes from front to rear. At the rear end this cylinder b is provided with a curved or spoon likelifter, e', (shown clearly in Fig. 2,) having its inner face corrugated. This lifter revolves with the cylinder, and at each revolution lifts up a quantity of the dry material from the bottom of the cylinder and carries it up between its corrugated face and the corrugated or tluted surface of a roller, f, Secured upon a shaft, f', and which revolves in an opposite direction to the cylinder. This shaft passes out through a discharge-pipe, f at the end of the cylinder,and is provided with a short screw-flight, f to aid in conveying off the material which is fed therein from the lifter. This conveyer-fiight is also cut short. allowing the material to mass in the pipe and form a plug to hermetically seal it against the admission of any air to the cylinder.

To prevent any scale from forming on the inside of the revolving cylinder, I secure the ends of a chain, g, to the inlet and. outlet ends of the cy1inder,and allow the body of the chain to lie upon the bottom ofthe cylinder,as clearly seen in Fig. 1. This chain acts as a scraper and keeps scale and particles of the soda from adhering to the metal.

In operation the bicarbonate and carbonate of soda are fed in proper quantities to the chamber c where they are mixed and fed through the tube e to the cylinder I), through which they slowly pass, and are taken up by the lift'er, all lumps broken by it and the corrugated roller, and finally discharged perfect earbonate of soda.

It is important that no air should be allowed to enter the cylinder, and this I aecomplish by allowing the material to aceunulate and form a plug, which seals all the eonneetions, but does not interfere with the continuous operat'on of the apparatus. This also prevents the escape of the steam and gases at these points, they being conpelled to pass up through the tube e and oylinder c and out through an opening, g', especially provided for them, and from which they are conducted off to any point desired.

Having thus fully described my invention, what I claim as new, and desire to secure by Letters Patent, is-- l. The combination, with a revolving roasting-cylnder and a furnace for heating the same, ofa mi'xing-chanber connected Io said eylinder and having an inlet for the bicarho nate and one for the carbonate, whereby a nixture is ma'de and fed continuously to the oylinder, substantially as and for the purpose set forth.

2. The combination, with the revolving roasting-cylinder, of an outlet for the soda provided with a eonveye shat having a corrugated roller on its end and a tangentiallyeurved lifter'within the cylinder formed with a corrugated face, whereby the material is continuously diseharged and all lumps crushed,'

substantially as and for the purpose set forth.

3. The eombination, with the miXing-chamber 'of an apparatns for decomposing bicarbonate of soda, of a hopper thereon having a feedng-valve in its bottom, and a pipe connected thereto and provided with a conveyer stopping short ofts oonneeting-point, whereby the material is indueed to fill the openings and prevent the admission of air, substantiall y as and for the purpose set forth.

4. The combination, with the 'otary roasting-cylinder, of a diseharge-pipe and a conveyer therein made shorter than the pipe, substantially as and for the purpose set forth.

In t-estinony whereof I have hereuuto set my hand, this 3lst day of December, 1887, in the presence of two witnesses, at Brussels, Belgum.

ERNEST SOLVAY.

WVitnesses:

P. LIENIENUL, T. A. FRsTENHoFF. 

